Louvered zigzag fin strip forming machine



Feb. 6, 1968 J. AVAKIAN LOUVERED ZIGZAG FIN STRIP FORMING MACHINE 2 Sheets-Sheet 1 Filed Aug. 18, 1965 INVENTOR HRANT J AVAK IAN ATTORNEYS H. J. AVAKIAN Feb. 6, 1968 LOUVERED ZIGZAG FIN STRIP FORMING MACHINE 2 Sheets-Sheet 2 Filed Aug. 18, 1965 mm m Faterited Feb. 6, 1968 3,367,161 LOUVERED ZIGZAG FIN STRIP FORMHNG MACHINE Hrant J. Avakian, 440 Geller-t Drive, San Francisco, Calif. 94132 Filed Aug. 18, 1965, Ser. No. 480,715 7 Claims. (Cl. 72186) ABSTRACT OF THE DISCLOSURE This machine continuously automatically forms metal ribbon coil stock into zigzag-convoluted fin strip material while at the same time it forms louvers in the convolutions for more efiicient deflection of the cooling air, then accurately spaces these convolutions and finally automatically cuts off the zigzag convoluted strip material into strips of accurately predetermined length.

The metal ribbon coil stock supplied to the machine is subjected to a frictional drag applied by an air-cylinderoperated drag device, so that the zigzag convolutions are precisely formed to accurately-controlled dimensions.

Toothed gathering rolls follow the toothed forming rolls for the purpose of precisely spacing the convolutions by the desired amount and maintaining that spacing up to the instant of cutoff into sections.

Adjustable-Width guides for the convoluted fin strip material emerging from the forming rolls and entering the gathering rolls thereby adapt the machine to the production of different widths of convoluted fin strips.

A pressure pad disposed between the forming rolls and the gathering rolls and preferably also beyond the gathering rolls applies a gradual frictional drag to the convoluted strip material.

A double-acting cutoff device which moves alternately in opposite directions to out off the continuous convoluted fin strip material into strips of predetermined length, thereby increases the speed of operation of the machine.

In the accompanying drawings:

FIGURE 1 is a top plan view of a louvered zigzag convoluted fin strip producing machine, according to one form of the invention, with the metal ribbon coil stock supply reel and guide rolls omitted; 4 I

FIGURE 2 is a vertical section through the machine of FIGURE 1, taken along the line 22 therein, with a portion of the metal ribbon coil stock supply reel and guide rollers added;

FIGURE 3 is an enlarged side elevation, in twice actual size, of a short length of the convoluted metal fin strip manufactured by the machine of FIGURES l and 2, with the convolutions spaced farther apart than in the finished fin strip, for clearness of showing; and FIGURE 4 is a vertical section taken along the line 44 in FIGURE 3, showing the louvers formed by the machine in each convolution.

- Referring to the drawings in detail, FIGURES 1 and 2 show a machine, generally designated 10, for forming zigzag-convoluted louvered fin strip material, according to one form of the invention. The machine has a supporting framework, generally designated 12, upon a bracket 13 of which is rotatably mounted a sheet metal ribbon coil stock supply reel 14. Metal ribbon coil stock'16 is unwound from the supply reel 14 arid fed between lowerand upper guide rolls 18 and 20 rotatably mounted upon axles 22 and 24 respectively supported between spaced parallel bracket plates 26. The latter are bolted or otherwise secured to the vertical edge faces 28 of laterally spaced parallel frame side plates 30, only one of which is shown in FIGURE 2. i i

A pressure-applying member 25 mounted on a swinging arm 27 is pivotedat 29 to the bracket plate 26.and engages.

the ribbon stock 16 on the supply reel 14 to prevent overrunning thereof upon halting of the machine 10. The arm 27 also operates a limit switch (not shown) which halts the driving motor of the machine 10 when the ribbon stock 16 runs out and has to be replenished or spliced. The arm 27 is swung toward the reel 14 and the pressure of the pressure-applying member 25 maintained by a reciprocatory pneumatic motor 31 pivotally mounted at 33 on the frame structure 12 and having a piston 37 pivotally connected at 35 to the arm 27. A horizontal shelf plate 34 is bolted between the side plates 30 and pivotally connected to it as by the yoke 36 and pivot member 38 is the cylinder 40 of a reciprocatory pneumatic motor, generally designated 42.

Reciprocably mounted in the pneumatic motor cylinder 40 (FIGURE 2) is a piston 44 which at its upper end carries a yoke 46 pivotally connected by a pivot member 48 to the initial pressure pad 49 of an initial frictional drag device 50. Bolted to and extending between the side plates 30 above the sheet metal ribbon stock 16 in vertically-spaced relationship to the pressure pad 49 is an abutment bar 52 against which the ribbon stock 16 is pressed by the pressure pad 50. Secured as by adhesives to the pad 50 and bar 52 are ribbon stock contact linings 53 of corrugated fiber sheeting. The pressure pad 50 exerts a drag upon the sheet metal ribbon stock 16 which controls the height of the zigzag convolutions 54 of the convoluted fin strip material 55 formed in the ribbon stock 16 by intermeshing upper and lower toothed forming rolls 56 and 58 respectively mounted on upper and lower spindles 60 and 62. The lower spindle 62 is journaled in the opposite side plates 30, whereas the upper spindle 60 is journaled in slides vertically guided in upstanding forward supporting extensions 64 of the side plates 30. The supporting portions 64 at their upper ends are interconnected by a bridge plate 66 bolted thereto and carrying near its opposite ends adjusting screws 68 threaded therethrough and at their lower ends connected to slides 70 mounted in vertical guideway slots 72. Lock nuts 74 secure the adjusting screws 68 in their adjusted positions. In this manner, the upper toothed forming roll 56 is movable toward and away from the lower toothed forming roll 58 to adjust the separation between them through which the metal ribbon stock 16 passes.

Each of the toothed forming rolls 56 and 58 consists of a plurality of toothed forming wheels 76 mounted side by side on their respective spindles 60 and 62 with their V-shaped teeth 78 and 80 respectively configured to simultaneously produce the V-shaped zigzag convolutions 54 and at the same time out parallel slits 82 therein and press out louvers 84 from each convolution wall 85 (FIG- URES 3 and 4). These louvers 84, when the convoluted fin strip material 55 is mounted in radiator cores, intercept the air passing through the radiator core and direct it laterally so as to increase the etficiency of the heatexchange or cooling action of the air on the water or other coolant passing through the radiator core. Bolted or otherwise secured between the opposite side plate extensions 64 immediately adjacent the exit or rearward side of the forming rolls 56 and 58 is a stripper bar 86.

Bolted or otherwise secured to and extending between the side plates 30 is a horizontal strip material supporting plate structure 88 having therein longitudinally-spaced openings 90, 92, 94, 96 and 98. The ribbon stock 16 and afterward the zigzag convoluted fin strip material 55 rest upon the bed plate 88 as they pass through the machine 10 from one end to the other. The lower forming roll 58 is mounted in and extends through the first opening in the bed plate 88, whereas a V-toothed feeding roll 100 with teeth 101 is mounted in and extends through the second opening 92 in the same bed plate 88 upon a spindle 102 journaled at its opposite ends in the side plates 30.,

Mounted in the third opening 94 in the bed plate 88 is an intermediate spring-pressed frictional drag device 104 and similarly mounted beyond the fourth opening 96 in the fifth opening 98 in the bed plate 88 is a similar final frictional drag device 106. Each frictional drag device 104 or 106 includes a spring abutment bar 108 extending between side plates 30 and supporting a plurality of compression springs 110, the upper portions of which are mounted shaped fin strip material 55 with its zigzag convolutions 54 containing parallel slits 82 and pressedout louvers 84 in each convolution wall 83 (FIGURES 3 and 4). These louvers 84, when the convoluted fin strip material 55 is mounted in radiator cores, direct air laterally to enhance the heat-exchange and cooling action. Mounted immediately adjacent the entrance and exit sides respectively of the forming rolls 56 and 58 are verticallyspaced horizontal cross bars 85 and 86 separated from one another by an opening 90.

Bolted or otherwise secured to and extending between the side plates 30 is a horizontal sectional bed plate 88 including longitudinally-spaced bed plate sections 89, 91, 93, 95 and 97 separated by openings 92, 94, 96 and 98 respectively. The zigzag convoluted fin strip material 55 produced from the ribbon stock 16 rests upon the bed plate 88 as it passes through the machine from the forming rolls 56, 58 to the other end thereof. The lower forming roll 58 is mounted in and extends through the first opening 90 in the bed plate 88, whereas a V-toothed feeding roll 100 with teeth 101 is mounted in and extends through the second opening 92 in the same bed plate 88 upon a spindle 102 journaled at its opposite ends in the side plates 30.

Mounted in the third opening 94 in the bed plate 88 is an intermediate spring-pressed frictional drag device 104 and similarly mounted beyond the fourth opening 96 in the fifth opening 98 in the bed plate 88 is a similar final frictional drag device 106. Each frictional drag device 104 or 106 includes a spring abutment bar 108 extending between side plates 30 and supporting a plurality of compression springs 110, the upper portions of which are mounted in guide housings 112 secured to and depending fromthe undersides of pressure pads 114 with longitudinally-extending tongues 115 projecting from opposite edges thereof in correspondingly-shaped openings 94 and 98. The pressure pads 114 urge the convoluted strip material 55 upwardly into engagement with horizontal abutment plates 116 and 118 bolted or otherwise secured to the upper edges of the side plates 30 immediately above the path of the convoluted strip material 55. As stated below in connection with the operation of the machine 10, the intermediate pressure pad device 104 exerts such a drag upon the convoluted strip material 55 as to alter the interval between convolutions immediately before the strip material 55 passes between the V-shaped teeth 119 and 121 of the upper and lower toothed gathering rolls 120 and 122 respectively which pull the convolutions 54 closer together and determine the final spacing of the convolutions 54. The lower toothed gathering roll 122 is mounted in the fourth opening 96 upon a spindle 124 journaled in the opposite side plates 30, whereas the upper toothed gathering roll 120 is mounted upon a spindle 126 journaled in slides 128 vertically slidably mounted in guide slots 130 and adjusted by means of adjusting screws 132 threaded through a bridge plate 134 near the opposite ends thereof. At is opposite ends, the bridge plate 134 is bolted or otherwise secured to upstanding rearward extensions 136 of the side plates 30.

The lower forming roll spindle 62 is driven through conventional reduction gearing from an conventional electric motor (not shown). The upper forming roll spindle 60 is driven from the lower spindle 62 through intermeshing gears 138 (FIGURE 1) keyed or otherwise drivingly secured to the rearward ends of the respective spindles. Meshing with one of the forming roll driving gears 138 is an idler gear 140 mounted on a stub shaft 142 which in turn is seated in the rearward side plate 30. The idler gear on its opposite side meshes with a gear 144 which is keyed or otherwise drivingly secured to the rearward end of the feeding roll spindle 102. Keyed or otherwise drivingly secured to the feeding roll spindle 102 is a pinion 146 which in turn meshes with an idler gear 148 mounted on a stub shaft 150 also seated in the rear side plate 30. The idler gear 148 in turn meshes with and drives a gear 152 keyed or otherwise drivingly secured to the rearward end of the lower gathering roll spindle 124. The lower and upper gathering roll spindles 124 and 126 are drivingly interconnected by a pair of intermeshing gears 154 keyed or otherwise drivingly secured to their respective spindles. This completes the drive gearing train interconnecting the spindles 60, 62, 102, 124 and 126.

Independently driven from the electric driving motor (not shown) of the machine 10 as by a sprocket chain (not shown) is the drive sprocket 156 of a convolution counter drive shaft 158 which furnishes the power input for a fin convolution counter, generally designated 160, mounted on the platform 162 secured to the upper edge of the rearward side plate 30. The convolution counter is conventional, available commercially, and its details are beyond the scope of the present invention. The housing 164 of the convolution counter 160 is hinged to the platform 162 near its rearward end and has an arm 166 (FIGURE 1) extending forwardly to an elongated slot 168 near its forward end. Extending downwardly through the slot 168 and threaded into the threaded hole in the upper edge face is a hand screw 170 which holds down the forward end of the arm 166. Journaled in the arm 166 and drivingly connected to the input shaft 158 is a convolution counting worm 172, the pitch of which corresponds to the desired separation for the convolutions 54 in the completed convoluted fin strip material 55. As explained below in connection with the operation of the invention, the convolution counter 160 contains a cutoff timing switch (not shown) which controls and brings about the cutoff of the convoluted strip material 55 into lengths containing a predetermined desired number of convolutions as governed by a predetermined number of revolutions of the convolution counting worm 172.

The cutoff of the convoluted strip material 55 into such lengths is carried out by a double-acting cutoff device, generally designated 174. The latter is provided with laterally-spaced parallel vertical guide bars 176 and retaining bars 178 both bolted to a vertical face plate 180 which in turn is bolted to the ends of the side plates 30. The face plate 180 immediately adjacent and in line with the fin strip material 55 emerging from the convolu tion counting worm 172 is provided with a laterally-elongated horizontal passageway 182 (FIGURE 2) through which the convoluted material 55 passes immediately prior to cutoff. Cutoff is accomplished by a cutoff plate 184 which is vertically reciprocable in the guideway 186 formed between the opposite guide bars and retaining bars 176 and 178 respectively (FIGURE 1). A sharpedged cutter bar 188 inclined slightly to the horizontal is bolted or otherwise secured to the cutoff plate 184 midway between upper and lower cutoff passageways or slots 190 and 192 respectively which have substantially the same cross-sectional dimensions as the passageway 182 so as to permit free passage of the convoluted fin strip material 55. The cutter bar 188 has upper and lower cutting edges 194 and 196 respectively which operate alternately to cut off the fin strip material 55, as explained below invconnection with the operation of the invention;

The lower portion of the cutter plate 184 is drilled for the reception of a pivot pin 198 which also is pivotally engaged by a yoke or cross head 200 mounted on the upper end of the piston 202 reciprocably mounted in the vertical cylinder 204 of a vertical pneumatic 1'Cip-- rocatory cutoif motor, generally designated 206. The cylinder 204 is mounted on the frame structure 12 of the machine 10 and is connected at its upper and lower ends to a conventional air valve solenoidally operated in response to the action of the timing switch within the convolution counter 160, so as to move the cutter plate 184 and its cutter bar 188 alternately upward and downward to execute cutoff strokes upon the convoluted fin strip material 55 each time the predetermined desired number of convolutions 54 has been counted off. In this manner, the double-acting cutoff plate 184 reduces the time of operation of the machine by cutting on its return stroke as well as on its forward stroke.

Bolted or otherwise secured to the sections 89, 91, 93, 95 and 9 7 of the bed plate structure 88 in laterallyspaced parallel relationship (FIGURE 1) are longitudinal guide bars 210, 212, 214, 216 and 218. These guide bars are laterally adjustable to accommodate the space between them to different widths of convoluted fin strip material 55, as required for different sizes and makes of radiator cores. These guide bars are preferably dowelled as well as bolted to their respective above-mentioned bed plate sections in order to accurately space them apart from one another as well as to render them adjustable to different separations by providing different sets of threaded bolt holes and dowel holes at different lateral spacings on said bed plate sections.

In the drawing, the frame structure 12 has been simplified, and various bolts and other fasteners omitted in order to make the disclosure more easy to understand.

In the operation of the invention, let it be assumed that a reel 14 of suitable ribbon stock 16, such as thin copper, has been mounted in the machine and that the pneumatic motor 31 has been operated to swing the arm 27 and pressure foot 25 from its retracted position of FIGURE 2 into frictional yielding engagement with the ribbon stock 16 on the reel 14. Let it also be assumed that the pressure pad 50 has been temporarily retracted by operating the vertical pneumatic motor 42 until the ribbon stock 16 has been threaded over the guide rollers 18 and 20 between the pads 50' and abutment bar and its end inserted between the forming V-toothed rolls 56 and 58, whereupon the motor 42 is reversed and the pressure pad 50 moved upward. Let it further be assumed that the adjusting screws 68 and 132 of the slides 70 and 128 have been moved upward or downward so that the teeth 78 and 80 of the forming rolls 56 and 58 and the teeth 119 and 121 of the gathering rolls 120 and 122 properly intermesh.

The operator now starts the driving motor (not shown) so as to rotate the forming rolls 56 and 58, the feeding roll 100, the gathering rolls 120 and 122 and the drive sprocket 156 of the convolution counter 160. As a consequence, once the forming rolls 56 and 58 have taken a bite upon the forward end of the metal ribbon stock 16, the latter is simultaneously converted into the zigzag convoluted strip material 55 while the cutting teeth on the forming rolls 56 and 58 cut the parallel slits 82 and press the louvers 84 outward from each convolution wall 85 (FIGURES 3 and 4). The thus-produced convoluted louvered strip material 55 is then moved forward (to the right in FIGURE 2) as it is stripped from the forming roll 56 by the stripper bar 86 and passes beneath the abutment plate 116 into engagement with the V-toothed feeding roll 108.

In response to the rotation of the feeding roll 100, the teeth 101 thereof enter the convolutions 54 and positively move the strip material 55 to the right over the intermediate pressure pad 114. Here the spring-pressed upward thrust of the pressure pad 114 of the pressure pad device 184 applies a frictional drag upon the convoluted strip material 55 as it passes beneath and against the abutment plate 116, causing the intervals between crests of the convolutions 54 to -be widened or, in other words, increasing the pitch of the convolutions. The convoluted strip material, after passing over and beyond the intermediate pressure pad 114, assisted by the longitudinallyextending tongues 115 thereof, passes into the space between the gathering rolls 120 and 122 and the convolutions 54 thereof are engaged and bent by the V-teeth 119 and 121 thereof into their final spacing or pitch.

The rotation of the gathering rolls 120 and 122 moves the now-finished strip material 55 through the space between the final pressure pad 114 of the final pressure pad device 106 and the abutment plate 118 above it and then is engaged by the rotating counting worm 172, which has the same pitch as the teeth 119 and 121 of the gathering rolls 120 and 122. As the worm 122 is rotated through its drive train within the housing 164 by its drive sprocket 156, it pushes the convoluted strip material 55 through the upper cutoff passageway 1 and performs a predetermined number of revolutions corresponding to a predetermined number of convolutions 54 constituting the desired length of each section of the convoluted strip material 55 to be cut off by each stroke of the cutter bar 188. When this number of rotations of the worm 172 has been accomplished, the counting mechanism within the housing 164 operates a switch (not shown) which actuates a solenoidal valve (not shown) which in turn supplies pneumatic pressure fluid to the lower end of the cylinder 204 of the cutoff motor 286, moving the piston 202, the cutter plate 184 and the cutter 188 sharply upward to the dotted line position shown in the upper right-hand corner of FIGURE 2, cutting off a section of the desired length of the convoluted strip material 55. The cutter bar 188 remains in its raised or dotted line position as the counting worm 172 continues to rotate and advance another length through the lower cutoff passageway 192, which is now aligned with the passageway 182.

When the counting worm 172 has again completed its predetermined number of rotations, it again causes the switch within the housing 164 to actuate the solenoid valve to reverse the flow of pneumatic fluid into the cylinder 204 of the pneumatic motor 206. This action causes the piston 202 to move sharply downward, thereby moving the cutter plate 184 and cutter bar 188 to move sharply downward from the dotted line position to the solid line position of FIGURE 2, cutting off another section of predetermined length of the convoluted strip material 55. This action goes on continuously, cutting off section after section of the strip material 55 until the ribbon stock 16 reaches its end upon the reel 14, whereupon the arm 27 operates a limit switch to halt the driving motor of the machine 10, as stated above. The ribbon stock 16 is then replenished and the operation of the machine continued in the above-described manner.

What I claim is:

1. A machine for continuously automatically forming ribbon coil stock into louvered zigzag convoluted strips of predetermined length, said machine comprising a framework,

an elongated zigzag strip-supporting structure mounted on said fnamework,

a pair of intermeshing toothed zigzag louvered strip forming rolls rotatably mounted on said framework respectively above and below said strip-supporting structure,

a toothed z gzag strip feeding roll rotatably mounted on said fnarnework beneath said strip-supporting structure with its toothed periphery projecting thereabove in longitudinally-spaced relationship to said forming rolls,

a pair of intermeshing toothed zigzag strip gathering rolls rotatably mounted on said framework respectively above and below said strip-supporting structure beyond said feeding roll,

an elongated zigzag strip abutment structure mounted above said strip-supporting structure in spaced parallel relationship therewith and defining a zigzag strip material passageway therebetween extending from said forming rolls to said gathering rolls,

a frictional drag device mounted beneath said stripsupporting structure and having a yieldingly-urged friction-applying member extending upwardly into said passageway,

a ribbon coil stock reel support mounted adjacent the forward end of said framework,

means for guiding ribbon stock from a reel on said reel support into the intermeshing teeth of said forming rolls,

a zigzag strip convolution counter disposed beyond said gathering rolls and having a convolution-counting element extending into said passageway into said engagement with the strip convolutions,

and a strip cutoff device mounted on said framework beyond said counter and responsive to each passage of a predetermined number of zigzag convolutions past said counter for severing a section of predetermined length from said zigzag strip material.

2. A machine, according to claim 1, wherein an intermediate frictional drag device is mounted on said framework between said strip feeding roll and said gathering rolls adjacent the path of travel of the zigzag convoluted strip material emerging from said feeding roll in yielding frictional engagement with said material.

3. A machine, according to claim 2, wherein said intermediate frictional drag device includes a spring-urged friction-applying pad extending upwardly into said path of tnavel of said strip material.

4. A machine, according to claim 2, wherein a final frictional drag device is mounted on said framework between said gathering rolls and said strip-cutoff device adjacent the path of travel of the zigzag convoluted strip material emerging from said gathering rolls in yielding frictional engagement with said material.

5. A machine, according to claim 4, wherein said final frictional drag device includes a spring-urged friction-applying pad extending upwardly into said path of travel of said strip material.

6. A machine, according to claim 1, wherein said strip cutofi device includes a double-acting reciprocatory cutter carrier mounted on said framework for travel alternately in opposite directions transversely to the path of travel of said strip material and having a pair of strip passageways 'therethrough spaced vertically apart from one another, wherein a strip cutter with a double-edged cutting blade is mounted on said cutter carrier in the space between said strip passageways, and wherein a poweroper ated reciprocating mechanism is operatively connnected to said cutter carrier and is operated in alternately opposite directions in response to each cycle of operation of said counter and in timed relationship therewith.

7. A machine, according to claim 6, wherein said mechanism includes a reciprocatory motor having a reciprocable plunger operatively connected to said cutter carrier.

References Cited UNITED STATES PATENTS Re 22,956 12/ 1947 Salzer 72-196 767,883 8/1904 Grafton 72-185 1,640,147 8/1927 Fedders et al 72-186 1,937,466 11/1933 Smith et al. 72-196 2,252,209 9/1941 Schank et al. 72-196 2,596,428 5/ 1952 OMalley 242-754 RICHARD J. HERBST, Primary Examiner.

L. A. LARSON, Assistant Examiner. 

